1. Field of the Invention
The invention relates to an ink jet recording head having at least four rows of nozzle openings in a main scanning direction with each row having a plurality of nozzle openings in a sheet forward direction. From such ink jet recording head, ink droplets are jetted out by pressure produced by pressure producing sources using piezoelectric elements, heating elements or the like.
2. Related Art
What has been proposed to improve dot density for better print quality is an arrangement in which four rows of nozzle openings extend in the carriage moving direction, i.e., in the main scanning direction. Such a nozzle arrangement is usually implemented by two sets of a recording head that has two rows, the nozzle openings in each row being staggered by a single dot in the sheet forward direction.
However, the second and third nozzle opening rows that are adjacent to each other in the middle are separated from each other by a housing forming member, and this not only increases the distance between the rows, but also requires an ink supply means. In addition, the operation of aligning the two heads is cumbersome as well.
Proposed to overcome the above problems is an integrated ink jet recording head in which four or more nozzle opening rows are arranged on a common nozzle plate and each nozzle opening has a pressure producing chamber thereof.
As shown in FIG. 10, such an integrated ink jet recording head is characterized as staggering the nozzle opening of each of the nozzle opening rows A, B, C, D by a single dot in the physically arranged order.
In this recording head, after driving the nozzle opening rows A, B, C, D in the physically arranged order, the nozzle opening rows are driven again cyclically in such physically arranged order. Thus, the carriage moves by a distance L1+L2+L3, which is the distance between the outermost rows, until the fourth nozzle opening row D printing a dot adjacent to the dot printed by the first nozzle opening A is driven. As a result, any inclination of the ink jet recording head accurring at the time of mounting the head or a change in the head mounting angle caused by play aggravates fluctuations in the distance between the dots printed by other nozzle opening rows, thereby impairing print quality.